2015-12-30

"Believe" is often associated with religion. However, even for using the "scientific method", we are forced to assume certain qualities of the Universe that we cannot prove nor fully verify. The most basic assumption is that there are common laws that are universal and they function the same across the whole Universe. This is a leap of faith that we have to take if we believe that the Universe can be understood at all by humans.

2015-12-21

Few people can be happy when basic needs are not met. When you are hungry or in pain it is unlikely that something would make you happy. Even with the basic needs fulfilled, many people have higher order needs, like being appreciated, achieving their highest potential.

"Noise cancellation" is a feature in recent high-end headphones that aims to actively remove the outside noise while listening music. You can also use them without music, however the efficiency is lower. "Noise cancellation" is a relatively new technology and you must be aware of what is reasonable to expect from such headphones.

2015-12-05

In a temperate musical octave, there are 12 possible
sounds. However, in a certain melody, usually, only 7 of them are used.
When you see, for example, "Symphony...in Do major", you should expect
that it is based on the white piano keys only. When using others scales, like
for "Symphony... in Re#", some of the white keys will be replaced by some of the
black keys.

2015-11-16

Studies on babies suggests that there is a certain morality sense we are birth with. Of course, this instinct must be developed and refined by society. It is, however, unlikely that our moral rules can become really disconnected with this moral instincts.

Most of these instincts are based on compassion. However there are also other emotions that shapes our common (punitive) moral sense. For example Contempt, Anger, and Disgust (CAD) appears as result of perceived violation of moral rules regarding Community, Autonomy, and Divinity (again CAD).

2015-10-19

I claim that most of the modern moral problems can be translated into "does this increases the likelihood of space colonization for humans?" This covers both traditional religious-based moral and more modern secular moral. You should take it with a grain of salt, of course ;), but let's see how it goes...

2015-09-01

I think that nobody should be coerced to vaccinate, himself or his child. I vaccinated my child because I considered that it is better like this. However, each person should have the right to choose for himself, ideally after knowing the true known risks of vaccinating and not vaccinating.

There is this theory that people that refuses to vaccinate prevents the full eradication of many diseases. They say that refusal to vaccinate not only affect the people that decides this, but also the people that vaccinate themselves but are in the small percent of people where vaccine is not effective.

I say we should take this risk of having not-vaccinated people in society. Here are some arguments:

2015-08-19

I watch my photo archive and I realize that my memory does not recall a lot of things. Even photos from couple of years back seems like pictures of events that happened to someone else. I remember when I took that picture, however it's like I see this for the first time.

The memory has a strange way to forget things. I still can't believe that my boy was that small. I know rationally, however I cannot recall the perception of him being that small. Pictures are not only anchors for memories, sometimes they are the only memories.

Our children are the first generation that can have, over years, a history in images of their entire life. Of course, we also have some pictures from childhood, but they are too few to create an image of continuity. Most of our childhood pictures are black&while and in studied positions (because of their scarcity) and looks more like taken from a movie/theater than from real life. The general availability of color digital pictures, sometimes including audio and movies, should change this perception. I will not discuss here the issues that are brought by the smartphones ;) And, of course, you must have a way to securely backup your pictures.

2015-07-08

We have a population of animals. Each individual can be associated with a certain "value", expressing his "fit level to the environment". We want to design a simple algorithm in the animal's genes that would make the individuals to mate close to optimal.

Let's say that resulting value for the mating is the product of the "value" of the two involved individuals. We will study the case when each individual can only be involved in mating with a single other individual.

In this conditions, the close to optimum mating is reached when mating is realized between individuals with very close values. Mathematically, we have a set of positive numbers (the values) and we want to create the pairs of numbers so that the sum of products of each pair will be maximal. This happens when we sort the numbers and we pair each number with the one next to it.

2015-07-04

My kid is close to 4 years and started to exhibit a very human brain process: before sleepping, he starts to remember random ideas and expresses them. Sometimes they are not only memories and plans he had over day, some are really new and original ideas - even that many are yet childish of course.

It is not something that could be related to a sudden thought association, he just has "ideas". It does not happen only before the sleep, it just happens more often then. Before the sleep it is also easier to eliminate hypothesis like "this thing remembered him about that other thing".

This process could show some light about how brain and neurons works, and possibly helping to design more human-like artificial intelligence. I would speculate that the same process that makes ideas and memories to pop up out of nothing, to be the process that permits the most amazing thought processes in humans.

2015-06-11

I should warn you that the requirement hides a trick and you will hate the solution. The program does not need to run efficiently. Actually, it does not need to run in reasonable time. It just has to be very short. And to be proven to answer the requirement, eventually... No external random source is allowed and no input from user.

2015-05-22

I will argue below that sorting of a big array by comparison is inherently harder than solving the problem of choosing the best reply move on a chess game.

One could say that it is not fair to put in competition a big, however finite, problem like chess with an arbitrary big problem like sorting n elements. Fair enough; the interresting thing is that sorting becomes inherently harder than chess for an "n" that is way smaller than you would expect, like sorting 3000 elements. At least in theory...

Sorting takes a minimum of n*log2(n) comparisons,

more exactly log2(n!)

This is about sorting "by comparison only" and can be proven in 2 step. You can skip to the "chess" part if you already know this.

1. Sorting can be done in log2(n!) comparisons, that is just slightly less than n*log2(n).
We are used to consider sorting an O(n*log2(n)) problem. Actually there are algorithms that can do the sorting with little less than n*log2(n) comparisons. The sorting by insertion in an increasingly sorted array takes log2(n!) comparisons.

2015-05-07

Will you have your digital pictures after 20 years from now? Will you regret to not have them? How can you safely store your digital pictures in order to still have them in 20 years or more?

I am talking, for example, about the pictures or movies that you take with your smartphone or with your digital camera. I know I will want to have them after years.

Digital pictures tends to be even more fragile than paper pictures. Do you still have all the digital pictures that you have taken 10 years ago? What if your smartphone gets stolen, or your desktop hard drive fails? What if you delete the pictures by mistake when re-installing the operating system?

Here are some ideas that I got when I evaluated the way to keep my pictures for 20 years or more. I am already using some of this methods for my pictures. I am open to other suggestions and comments.

General considerations

No single solution for storing
digital content is perfectly safe for 20 years or more

The best
solution should be a combination of solutions, hoping that at least one
will prove to be reliable

I will examine various solutions, with pros(+)
and cons(-). For assuring "disaster recovery" one should be a bit paranoid,
so here are some ideas:

2015-04-11

Sometimes the phone is connected to a charger, it reports "charging", however the battery level increases painfully slow, or it could even actually decrease. What is the solution?

On short:

For phones, prefer the 1A ("phone") charger port to the 2A ("tablet") charging port. The 2A port is likely to charge slower than the 1A port (see below why).

Use the original cable if possible. If not possible, USB charging cables that comes with cheap 1-2A chargers are usually better than more expensive "data and charging" cables. Prefer small cables (like 1m) or charging cables explicitly rated (ideally 2.5A or more).

Use dedicated chargers, not USB. Power wall or car chargers rated 800mA or more are usually way better than PC/Laptop USB ports. Prefer USB3 (blue) ports over USB2 (black). Some other USB colors (like orange/red) could be better than USB3 sometimes (or not).

Some devices might require an original power adapter (for example older Apple devices)

Update 2017: try using a charger rated Qualcomm Quick Charge 3.0 (or at least 2.0) if your device supports it. The device might negotiate 9V or 12V instead of 5V, resulting in 2-4 times faster charge until 80%. Also, PowerIQ and VoltageBoost might help if the device does not support QC.

Update 2016: For a faster feedback in your tests, try to install a phone application that reports the current (charging rate). A very light application that I found on Android is "OPO Charging Current". On my Android 5.1.1 (Nexus5) you have to divide by 1000 to obtain mA, but it just works. You can choose any other current monitoring application you prefer that works on your phone. Search for "charging current" for example.

2015-01-15

What gives value to money? There was a time when money was pure gold. There was a time when money was a certificate that you own a quantity of gold in bank (banknotes). Now the money are just quality paper, without any deposit behind. How that it has any value?

Some said that money is just a convention, and the fact that the state accepts that coin as the "legal tender" gives it value. However, we know many coins that loosed theirs value even with the state sustaining it. How that other coins survives?

I claim that debt is the one that gives value to the today's money. Let's see why: